In order to replace old lines, it is known to destroy them from the inside. Older pipers are typically cut or broken up prior to being replaced with newer pipes, and the new pipe is inserted into the broken older pipe. For example, in the “burst lining method”, the old pipe is broken up or taken apart with the aid of a bursting or cutting tool and forced into the ground at the side. For this purpose, a bursting or cutting head is moved through the old pipe route with the aid of a pulling or pushing apparatus and the pipe casing is pressed into the ground surrounding the pipe with the aid of a following expanding head A device of this type is disclosed, for example, in WO 02/076691 A2. A disadvantage of the device described therein is that the device can only ever be effectively used for a narrow diameter range of the pipes which are to be split. To split pipes outside this narrow diameter range, a new device specially adapted to this diameter range has to be produced.
WO 02129304 A1 discloses a device for splitting pipes from the inside, in which a cutting element is mounted in a radially movable manner with respect to the longitudinal axis of a main body and a mimic is provided for diverting pulling or pushing forces acting on the device into a radial movement of the cutting element. The radially movable cutting element permits conventional ductile cast iron pipes, and other pipes which can be difficult to destroy, to be taken apart with low pulling forces without problems occurring even at brackets, sockets or repair points which have a thickening of the material. By the pulling or pushing force acting on the tool being deflected into a radial movement of the cutting element, as the pulling or pushing load increases, for example during cutting of a socket, the cutting element is deflected radially. As a result, even pipe sections of this type can readily be severed. This device also has a defined diameter range of pipes which can be split up, in which it can be used. Pipes having a larger diameter cannot be split up by this device.
Against this background, the object of the present invention is a device and a cutting system and a method for splitting up pipes which enable pipes over a greater diameter range to be split.